Project Summary/Abstract: The overarching goal of Dr. Richardson?s research has been to identify the molecular pathways that lead to aging with the purpose of generating therapies that retard aging, delay/prevent age-related diseases, and improve the health of the elderly. His VA research has focused on the role oxidative stress and damage play in aging that has led to his recently funded VA Merit grant, which studies the role of inflammation in aging. Chronic, low-grade inflammation is a hallmark of aging and is a major risk factor for most age-related diseases, e.g., cancer, health disease, Alzheimer?s disease, etc. Necroptosis is a recently identified pathway of programmed necrosis that induces cell death through the lysis of cells, resulting in the release of damage-associated molecular patterns, which are potent inducers of inflammation. Using genetical manipulations that reduce necroptosis in mice, Dr. Richardson will determine if reducing necroptosis attenuates the age-related increase in chronic inflammation and leads to increased lifespan, improved healthspan, and reduced age-related pathology in the mice. Dr. Richardson also is PI on three NIH grants. His first NIH grant studies dietary Restriction (DR), which has been shown to increase the lifespan of a wide variety of organisms ranging from invertebrates to rodents. Therefore, DR has been viewed as a universal aging intervention. However, a study in 2010 reported that the genotype of an animal was a major determinant in the ability of the animal to respond to DR, e.g., two-thirds of the 41 recombinant inbred (RI) lines of mice studied either did not respond or showed reduced lifespan when fed DR. The overall goal of his NIH grant is to explore the interaction between genotype and the level of DR using four of the RI lines of mice reported to show a decrease in lifespan when fed a DR diet. The lifespan and pathology associated with aging is being measured in male and female mice fed either ad libitum or 60% ad libitum (DR). The current data indicate that in contrast to the previous report, DR increases the lifespan of the RI lines of mice, supporting the view that DR is a universal aging intervention. Dr. Richardson?s second NIH grant is in response to an RFA to develop measures of resilience in mice that can be surrogates for increased longevity and healthspan. He is developing four measures of resilience that are relatively simple, inexpensive, non-invasive, and can be performed in mice in vivo. Currently, his laboratory is studying the response of age, DR, and rapamycin on resilience to the following: treadmill exercise, recovery from anesthesia, carrageenan-induced inflammation, and recovery from oxidative stress. In a recently funded third NIH grant, Dr. Richardson is studying the potential role epigenetics plays in the anti-aging mechanism of DR. Recently, he showed that short-term DR induces changes in DNA methylation in intestinal mucosa in the promoter of the Nts 1 gene. The changes in DNA methylation were closely associated with increased expression of Nts 1, which persisted when the DR mice were then fed ad libitum for several months. Because the epithelial cells in the intestinal mucosa are continuously renewed every 4 to 5 days, the changes in DNA methylation in intestinal mucosa most likely arise in intestinal stem cells. In this grant, Dr. Richardson is measuring changes in DNA methylation induced by DR in intestinal stem cells using a novel assay, which allows him to measure accurately at single base resolution changes DNA methylation at ~30 million sites in the genome. In addition to his research grants, Dr. Richardson is also the PI/Director of a P30 NIA Center grant: the Oklahoma Nathan Shock Aging Center. The Oklahoma Shock Center involves faculty from the three major research institutions in Oklahoma City: University of Oklahoma Health Sciences Center, Oklahoma Medical Research Foundation, and OKC VA Medical Center. The Center plays provides faculty, post-doctoral fellows, and graduate students at the three institutions with unique assays to study aging and pilot grants.